One-Rep Max: Are You Lifting Heavy Enough?


Robert and Denise lifting heavy weights after taking their one-rep max test during Cathe's STS workout series.

By now, you know that unless you’re a complete beginner, you won’t see your muscles grow or build significant strength using small, pink weights. Your muscles need more stimulation than that. Yet, how do you know if you’re lifting enough to meet your goals? You might THINK you’re lifting heavy enough but, in reality, your muscles have adapted to the stress you’re placing on them. That means it’s time to increase the weight. Plus, if you’re just starting out, you might have no idea what weight you should choose. Selecting the correct resistance is one of the most important training decisions you can make.

The weight that you choose will depend upon what your fitness goals are. Is your main goal to get stronger or are you mainly focused on building muscle size and definition? The optimal weight will vary depending on what you’re trying to achieve. Even after you determine the best weight and number of reps, that will change as you progress toward your goal. As your muscles adapt to the stress you place on them, you must follow the principle of progressive overload and add more resistance. Otherwise, your workout will become stagnant and you’ll stop making gains. Nothing more frustrating than working out and not seeing changes!

Unfortunately, many women DO become stagnant because they stick with the same resistance and the same number of reps for weeks, months, and sometimes longer or they fear that going heavy will cause them to bulk up. That fear, for most women, is unfounded. So, if you’re wondering why you’re not making gains, look at the resistance you’re using and make sure you’re using enough to challenge yourself by taking a one-rep max test.

Choosing the Correct Weight

One way to determine the right weight for your goals is to do the one-rep max test. Your one-rep max is the heaviest weight that allows you to do one complete rep. Once you know your one-rep max, you lift at a percentage of that value. The percentage you choose will depend on what your training goals are. If you’re building strength, you’ll lift at a higher percentage of your one-rep max than if you’re only working on muscle endurance.

First, how can you measure your one-rep max? The easiest way to do this is to use a one-rep max calculator, like on our website. The calculator will tell you what your one-rep max is based on how many times you can lift a particular weight. To test yourself, choose a weight you think you can lift around ten times. Always warm up beforehand and then do as many reps as you can using that weight. Plug that value into the one-rep max calculator, along with the weight you used, and it should give you your one-rep max. This is an easier way to measure your one-rep max as opposed to trying to find a weight you can only lift one time and then struggle to lift it.

Your one-rep max is a measure of your maximal strength but it’s also a helpful parameter you can use to make the most of your workouts. Choosing the right weight, based on your one-rep max, will help you make faster gains and increase the odds that you DO make gains. When you choose a weight that’s an appropriate percentage of your one-rep max and not one that’s lighter, you know you’re working hard enough.

How to Use Your One-Rep Max

Once you know your one-rep max, consider your goals. Is your main objective to build strength? Then, you’ll want to lift at a high percentage of your one-rep max, around 90 to 95% of that value. You can use a one-rep max calculator to tell you what weight to use and how many reps you should aim for, based on your one-rep max. Typically, you’ll be able to do 2 to 5 reps using a weight of this magnitude. Since lifting this heavy is taxing on your nervous system, don’t do it every workout and give yourself adequate recovery time between sessions.

Is your primary goal to build muscle size? Select a weight that’s around 80% of your one-rep max. Again, you can use the calculator to tell you what weight will work best, based on your one-rep max. You will likely be able to lift a weight this heavy between 8 and 12 times. The higher number of reps works best for muscle hypertrophy but is not as effective for building maximal strength, although your strength will increase as well as your muscles grow.

If you lift at a lower percentage of your one-rep max, you’re targeting muscle endurance. For muscle endurance training, choose a weight that’s between 60 to 70% of your one-rep max and do as many reps as possible. You should be able to do between 12 and 20 reps. When you use a weight that you can lift more than 20 times and aren’t fatigued, you’re probably not getting a lot of benefit in any capacity and need to increase the weight.

Periodize Your Efforts

If you’re trying to build strength and lifting at 90% of your one-rep max, it’s exhausting to your nervous system. One way to avoid excessive fatigue while still getting the benefits is to periodize your workouts using an undulating scheme. With an undulating, rather than a linear, periodization model you alternate heavy, low-rep sessions for strength and lighter weights and higher reps for recovery, either on a daily or weekly basis. Doing this gives your muscles reprieve from constantly lifting heavy. Because you’re varying the stimulus you place on your muscles, it also helps avoid plateaus.

The Bottom Line

If you’re trying to build strength, don’t shy away from lifting heavy weights. It’s the only way to reach your goals. Use the one-rep max test and a calculator to ensure you’re using the correct weight. There are so many reasons to challenge yourself when you lift that go beyond aesthetics. Lifting heavy helps stimulate your bones to lay down new, healthy bone tissue and helps reduce the loss of muscle we all experience as we age. Some studies even show that weight training lowers blood pressure, making it a heart-healthy pursuit as well. So, keep lifting and make sure you’re lifting hard enough!



ExRx.net. “Predicting One-Rep Max”
Human Performance Resource Center. “One-Rep Max for Strength”
1 RM Strength Testing by Len Kravitz, Ph.D., Kenneth Nowicki, M.S., and Stephen J. Kinzey, Ph.D.


Related Articles By Cathe:

2 Types of Periodization and How They Differ

The Best Ways to Build Muscle Endurance & Why You Should

Strength Gains: 5 Reasons You’re Not Getting Stronger

Is There a Threshold Intensity at Which You Need to Train for Muscle Growth?

Can You Build Strength Lifting Lighter Weights?

What Role Does Mechanical Tension Play in Muscle Hypertrophy?


Related Cathe Friedrich Workout DVDs:

STS Strength 90 Day Workout Program

All of Cathe’s Strength & Toning Workout DVDs
Total Body Workouts
Lower Body Workouts
Upper Body Workouts


Hi, I'm Cathe

I want to help you get in the best shape of your life and stay healthy with my workout videos, DVDs and Free Weekly Newsletter. Here are several ways you can watch and work out to my exercise videos and purchase my fitness products:

Get Your Free Weekly Cathe Friedrich Newsletter

Get free weekly tips on Fitness, Health, Weight Loss and Nutrition delivered directly to your email inbox. Plus get Special Cathe Product Offers and learn about What’s New at Cathe Dot Com.

Enter your email address below to start receiving my free weekly updates. Don’t worry…I guarantee 100% privacy. Your information will not be shared and you can easily unsubscribe whenever you like. Our Privacy Policy